OK I read your first two posts, gagged a little bit, and then proceeded to hit the "Reply" button without reading the rest of the posts, so excuse me if I'm repeating anyone.
Eating doesn't seem to do the trick? Eat more. I'm serious. There's no such thing as a person with a metabolism SO fast that eating enough won't put on mass. If it takes 5000 calories a day, do it. And no, you shouldn't just eat anything. Eat healthy foods, but they're not hard to come by.
You will NEED a food log, and you will have to come to terms with the fact that you will have to
a) spend more time in the kitchen then you already do
b) clean the kitchen more than you are
c) take shit from people calling you a health freak
d) eat so much you feel like puking
e) probably puke at least once trying to eat so much food
f) shop EVERY WEEK
g) spend more money on food than you are
I think that covers it. I won't go into the details of what foods you should eat, check out Berardi's 7 Habits of Highly Effective Nutrition Plans (or something) article first, then Massive Eating I and II. Make a food log, and try to break 3000 calories from now (I bet you're not, even though you think you might). Do this for 2-3 months. If you still aren't gaining weight, move up to 3500. Hell, why not start at 3500 if you can manage it. The point is it will suck, you'll hate it, and you'll probably quit and take steroids, but it's definitely possible, you just have to want it bad enough.
As far as supplements, I wouldn't bother with them for now. Supplements SUPPLEMENT your diet. Get that down first, and then ask some people who know about them (not me) and find out which you should take. The only product you should buy is Grow! powder, and Grow! bars if you want. The Grow! will help you add some protein, cuz trust me it's hard to eat chicken with oatmeal. Once you get your diet in good order, then look to other supplements. Hell, MRPs aren't even supplements.
Training? I don't know. Westside for Skinny Bastards if you want. I just use my own program. Hit the big core lifts and don't be a pussy. The more hormonoes you release with each lift (read, do core lifts) the bigger you'll get. If you don't squat, deadlift, press, or row, you fail at life.
Go have fun.